McDean began his photographic career in London as a photographer's assistant to photographer Nick Knight.[1] His early editorial work was featured in magazines such as i-D and The Face, which led to advertising campaign work for clients such as Jil Sander and Calvin Klein, and editorial commissions with Harper's Bazaar and Vogue.

McDean is married to former model and stylist Tabitha Simmons, who is also a contributing fashion editor with Vogue. The couple lives in Chelsea, Manhattan.[1] He is represented by Art + Commerce in New York.[2]